A method of beneficiating weathered ilmenite

Abstract

The application discloses a beneficiation method of weathered ilmenite, and belongs to the technical field of mineral processing. The combined process of'stage iron selection + strong magnetic pre-concentration + multi-stage spiral chute separation + strong magnetic separation + suspension conical surface separation' is adopted to realize efficient recovery of the weathered ilmenite, and separation indexes of a concentrate grade of more than 46% and a recovery rate of 70-78% are obtained. The suspension conical surface separator can realize fine separation of the titanium-containing middlings, and compared with the conventional spiral chute and shaking table, the recovery rate of the ilmenite concentrate can be increased by 5-10 percent points, and the concentrate grade can be increased by more than 3 percent points. The application can avoid over-grinding, save the cost, improve the recovery efficiency, and has a wide application prospect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of mineral processing, and particularly relates to a beneficiation method of weathered ilmenite. BACKGROUND

[0002] Titanium is a rare metal resource. Titanium and its alloys are widely used in medical devices, coatings, aerospace, catalysis and military industries due to their excellent physical and chemical properties. China has the largest reserves of titanium resources in the world, but 95% of which is contained in primary vanadium-titanium magnetite, mainly distributed in the Panxi region and Chengde region. The second is ilmenite sand mine, mainly distributed in Yunnan, Hainan and Guangdong, etc., and the mine points are relatively scattered. According to the degree of weathering, the titanium ore resources can be divided into weathered titanium ore, semi-weathered titanium ore and primary titanium ore, which are distributed in layers (zones) from shallow to deep. Weathered ilmenite has the characteristics of high weathering degree, high clay content and loose structure. Titanium is mainly contained in ilmenite and titanomagnetite, and the gangue mineral is mainly clay mineral, with a content of usually more than 70%.

[0003] At present, efficient separation of weathered ilmenite has been a difficult problem in ilmenite processing field. Because most of the titanomagnetite and ilmenite particles are tightly wrapped with clay minerals, and the embedded particle size of iron and titanium minerals is uneven, it is the key to realize the monomer dissociation of target minerals and develop a separation process matching the ore characteristics. Over-grinding phenomenon is easy to occur during grinding of such ores, and the fine-grained ilmenite mixed with slurry is difficult to recover. The existing physical separation is mainly based on strong magnetic separation pre-concentration and conventional gravity separation, which only obtains titanium concentrate with 40-45% titanium dioxide content and 40-50% recovery rate, resulting in serious resource waste. On the other hand, due to the existence of a large amount of slurry, efficient recovery of weathered ilmenite by flotation also faces many challenges.

[0004] There are some reports on weathered ilmenite. The invention patent CN118218120 A discloses a "ultrasonic coupling separation process for fully weathered ilmenite", which uses ultrasonic coupling mechanical stirring to reduce the grinding cost, reduce the fine particle output and improve the recovery rate. However, this process uses strong magnetic concentrate pre-classification, table gravity separation and middlings return method, which has the disadvantages of relatively complex process, large table area, and easy accumulation of middlings return to affect the separation effect. Therefore, the existing process needs to be improved, and the development of beneficiation method of weathered ilmenite has great practical significance for the efficient development and utilization of such ores. SUMMARY

[0005] To solve the above technical problems, the application provides a beneficiation method of weathered ilmenite, and the weathered ilmenite is efficiently recovered through the combined separation of'stage iron separation + strong magnetic pre-concentration + multi-stage spiral chute separation + strong magnetic separation + suspension conical surface separation' according to the principle of stage grinding and stage separation.

[0006] To achieve the above object, the application provides the following technical scheme.

[0007] The application provides a beneficiation method of weathered ilmenite, and the iron concentrate and the titanium-containing iron middlings are obtained by adopting stage grinding and stage weak magnetic separation; the strong magnetic concentrate and the strong magnetic tailings are obtained by performing strong magnetic rough separation on the weak magnetic tailings; the spiral chute products are obtained by performing three times of spiral chute separation on the strong magnetic concentrate, and the spiral chute products include spiral chute rough concentrate, spiral chute middlings and spiral chute tailings; the titanium concentrate and the strong magnetic titanium middlings are obtained by performing closed-circuit grinding and strong magnetic separation on the spiral chute rough concentrate; the titanium concentrate is obtained by performing secondary suspension conical surface separation on the spiral chute middlings, the titanium-containing iron middlings and the strong magnetic titanium middlings after grinding, so that the weathered ilmenite is efficiently recovered.

[0008] Further, the beneficiation method of weathered ilmenite comprises the following steps.

[0009] (1) the raw ore of weathered ilmenite is ground and then subjected to wet weak magnetic separation to obtain weak magnetic rough concentrate and weak magnetic tailings;

[0010] (2) the weak magnetic rough concentrate is ground and subjected to wet weak magnetic separation to obtain iron concentrate and titanium-containing iron middlings;

[0011] (3) the weak magnetic tailings are subjected to strong magnetic rough separation to obtain strong magnetic concentrate and strong magnetic tailings;

[0012] (4) the strong magnetic concentrate is subjected to first spiral chute separation to obtain spiral chute I rough concentrate, spiral chute I middlings and spiral chute I tailings;

[0013] (5) the spiral chute I rough concentrate obtained in step (4) is subjected to second spiral chute separation to obtain spiral chute II rough concentrate, spiral chute II middlings and spiral chute II tailings;

[0014] (6) the spiral chute II rough concentrate obtained in step (5) is subjected to third spiral chute separation to obtain spiral chute III rough concentrate, spiral chute III middlings and spiral chute III tailings;

[0015] (7) the spiral chute III rough concentrate obtained in step (6) is subjected to closed-circuit grinding and strong magnetic separation to obtain titanium concentrate and titanium middlings;

[0016] (8) grinding the screw chute middlings (i.e. screw chute I middlings, screw chute II middlings and screw chute III middlings) obtained in steps (4)-(6), and performing rough separation on the screw chute middlings and the titanium-bearing iron middlings obtained in step (2) and the titanium middlings obtained in step (7) by using a suspension cone separator to obtain a rough concentrate and a tailing;

[0017] (9) performing fine separation on the rough concentrate obtained in step (8) by using a suspension cone separator to obtain a titanium concentrate and a tailing.

[0018] The principle of the present application is as follows: based on the difference in mineral magnetism, strong magnetic iron minerals are recovered first by stage weak magnetic separation, which realizes effective recovery of iron minerals and creates good conditions for subsequent titanium separation process. The impurities containing kaolin and other non-titanium minerals are effectively removed by strong magnetic separation, and the concentration of ilmenite minerals in the subsequent steps is significantly improved. On this basis, based on the difference in mineral particle size and density, the continuous processing chain of rough concentrate is realized by multi-stage spiral chute separation, which promotes the effective separation and concentration of titanium minerals in any stage. On this basis, the monomer dissociation degree of the minerals is further improved by fine grinding, and the difference in specific magnetic susceptibility of the minerals is utilized to realize effective enrichment of ilmenite by strong magnetic separation, so as to ensure that the titanium concentrate obtained finally has higher TiO2 content. For the middlings rich in micro-fine ilmenite, according to the Bingham shear loose theory and the flow film separation principle, different densities of minerals are sequentially brought into the tailing tank, the middling tank and the concentrate tank by the suspension cone separation, so as to realize effective separation of micro-fine ilmenite and improve the total titanium recovery rate.

[0019] Further, in step (1), the size of the crushed ore of the weathered ilmenite is 2-5 mm, and the grinding is to a fineness of -74 μm particle size content of 45-65 wt%; and / or

[0020] The magnetic field strength of the wet weak magnetic separation is 0.15-0.2 T.

[0021] Further, in step (2), the grinding is to a fineness of -38 μm particle size content of 75-85 wt%, and the suitable grinding fineness can make the grade and recovery rate of the titanium concentrate reach the best balance; and / or

[0022] The magnetic field strength of the wet weak magnetic separation is 0.1-0.15 T, and the increase of the magnetic field strength helps to improve the recovery rate, but reduces the grade of the titanium concentrate, so the suitable magnetic field strength can make the grade and recovery rate of the titanium concentrate reach the best balance.

[0023] Further, in step (3), the magnetic field strength of the strong magnetic rough separation is 0.8-1.2 T. The magnetic field strength has a significant influence on the magnetism of the ore, and further influences the behavior in the magnetic separation and the grade of the final concentrate, and the suitable magnetic field strength can make the grade and recovery rate of the titanium concentrate reach the best balance.

[0024] Further, in steps (4)-(6), the concentration of the feed ore is 40-60wt%, the longitudinal inclination is 0.6°, and the horizontal inclination is 9° during the spiral chute separation. The concentration of the feed ore has a significant impact on the separation effect of the spiral chute. If the concentration of the feed ore is too large, the viscosity of the ore pulp increases, the ore layer is not easy to loosen, the particle settling is blocked, the layering effect and the movement speed of the particles are seriously affected, and thus the concentrate grade and the recovery rate are reduced. If the concentration of the feed ore is too small, the processing capacity per unit time is reduced, the ore layer is thinned, the layering and zoning are not possible, the flow rate of the ore pulp is increased, the useful heavy minerals are not layered and settled in time and are discharged, the tailings grade is increased, and the separation efficiency is reduced. The intersection angle between the tangent of the spiral chute cross-sectional curve and the vertical axis is called the longitudinal inclination. The greater the longitudinal inclination, the faster the flow rate of the ore pulp, and the greater the centrifugal force on the material. A suitable longitudinal inclination can make the ore pulp flow along the groove body, obtain good ore dressing indicators, and improve the efficiency of ore dressing. The horizontal inclination and the longitudinal inclination are complementary. The transverse inclination also affects the distribution of the ore pulp flow on the groove surface. The greater the transverse inclination, the greater the water flow depth. A suitable transverse inclination helps to optimize the separation process of the material, thereby affecting the final grade of the titanium concentrate.

[0025] Further, in step (7), the classification closed-circuit grinding takes 0.05mm as the classification limit, grinds the +0.05mm material (i.e., the ore with a particle size greater than 0.05mm), and takes the -0.05mm material (i.e., the ore with a particle size less than 0.05mm) as the qualified product; and / or

[0026] The magnetic field strength of the high-intensity magnetic separation is 0.6-0.8T.

[0027] Further, in step (8), the grinding is to a fineness of -74μm particle size content of 85-95wt%; and / or

[0028] The rotation frequency of the suspension cone separator is 15-20Hz, and the vibration frequency is 15-20Hz.

[0029] Further, in step (9), the rotation frequency of the suspension cone separator is 10-15Hz, and the vibration frequency is 15-20Hz.

[0030] In the suspension cone beneficiation process, if the vibration frequency is too large, the vibration of the disc surface is strengthened, the shearing movement between the ore particles is enhanced, and the loosening of the ore layer is also increased, which leads to a part of the titanium-containing minerals being washed away by the separation medium under the strong vibration of the disc surface, thereby reducing the recovery rate. The rotation speed of the separation surface directly determines the residence time of the separated materials on the device, that is, it affects the movement time of the particle group on the separation surface, and thus has a major impact on the movement trajectory. Therefore, it plays a decisive role in the grade and recovery rate of the concentrate. When the rotation speed of the separation surface is too large, the residence time of the materials on the separation surface is too short, and the particle group has not yet loosened, layered or incompletely layered, which leads to the minerals not being timely removed but directly taken to the concentrate tank under the action of gravity and washing water, thereby reducing the concentrate grade. When the rotation speed is too low, the materials on the separation surface stay for too long, and the heavy mineral particles that have completed the separation enter the tailings tank under the action of the separation surface vibration, gravity and washing water, thereby reducing the concentrate recovery rate.

[0031] Compared with the prior art, the present application has the following advantages and technical effects:

[0032] (1) The present application proposes a stage grinding and stage separation process, which not only reduces the grinding cost and obtains high-quality iron concentrate, but also reduces the influence on the subsequent titanium separation.

[0033] (2) The present application can effectively recover ilmenite, reduce energy consumption and save cost through the process of "stage iron separation + strong magnetic pre-concentration + multi-stage spiral chute separation + strong magnetic separation + suspension cone separation".

[0034] (3) The present application can improve the ilmenite concentrate recovery rate by 5-10 percentage points and the concentrate grade by more than 3 percentage points compared with conventional gravity separation through the fine separation of the suspension cone concentrator on the titanium-containing middlings. BRIEF DESCRIPTION OF DRAWINGS

[0035] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification. The illustrations are shown to explain the application and are not intended to limit the application in any manner. In the drawings:

[0036] Figure 1 The beneficiation process flow chart of weathered ilmenite provided by the present application. DETAILED DESCRIPTION

[0037] The detailed description of the various exemplary embodiments of the present application should not be considered as limiting the application, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the application.

[0038] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. Additionally, for a range of values of, an intermediate value of is specifically contemplated. Each of these intermediate values is also encompassed within the scope of the present application. The upper and lower limits of these smaller ranges can independently be included or excluded in the ranges.

[0039] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Although preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application. All documents mentioned herein are incorporated by reference to disclose and describe in detail the methods and / or materials which are related to the present application. In the case of conflict between the present specification and any document incorporated by reference, the present specification will control.

[0040] Many modifications and variations of the present application described in the specific embodiments of the application can be made by those skilled in the art without departing from the spirit or scope of the application. Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application. The specification and examples are illustrative only.

[0041] As used herein, the terms "comprise", "comprising", "include", "including", "have", "having", "contain", "containing", "characterized by" and the like can be used interchangeably.

[0042] The beneficiation process flow chart of weathered ilmenite provided by the present application is shown in Figure 1

[0043] The present application adopts the combined process of "stage iron selection + strong magnetic pre-concentration + multi-stage spiral chute separation + strong magnetic separation + suspension conical separation" to realize the efficient recovery of weathered ilmenite, and obtain a separation index of concentrate grade of more than 46% and recovery rate of 70-78%. The suspension conical separator in the present application can realize fine separation of titanium-containing middlings, and compared with conventional spiral chute and shaking table, it can improve the recovery rate of ilmenite concentrate by 5-10 percentage points and the concentrate grade by more than 3 percentage points. The present application can avoid over-grinding, save cost, improve recovery efficiency, and has broad application prospect.

[0044] ​The magnetic system of the wet magnetic separator is usually made of high-quality ferrite material or a composite of ferrite material and rare earth magnetic steel. The working principle of the wet magnetic separator is to separate different minerals in the magnetic field of the magnetic separator according to the magnetic differences of the minerals. When the mineral particles with different magnetic properties pass through the magnetic field of the magnetic separator, the mineral particles with different magnetic properties will produce different trajectories due to the different magnetic forces acting on them, thereby realizing the separation of different minerals. The magnetic field strength of the wet low-intensity magnetic separation is relatively low, and the magnetic field strength of the wet high-intensity magnetic separation is relatively high.

[0045] The "feed concentration" refers to the content of solid mineral particles in the ore pulp fed into a certain operation or device in the beneficiation process.

[0046] The intersection angle between the tangent of the spiral groove cross-sectional curve and the vertical axis is called the longitudinal inclination angle, and the horizontal inclination angle is complementary to the longitudinal inclination angle.

[0047] The "rotation frequency" of the suspended cone separator refers to the number of rotations of the separation cone per unit time, which is usually expressed in hertz (Hz). The rotation frequency is one of the important parameters that affect the beneficiation effect, and it determines the residence time of mineral particles on the separation disc and the size of the centrifugal force they receive. The "vibration frequency" refers to the vibration frequency of the separation disc, which is one of the core process parameters of the suspended cone separator. The vibration frequency determines the motion state of the mineral particles on the device, and it affects the motion speed of the mineral particles on the separation disc and the looseness between light and heavy minerals in the bed. In the suspended cone separator, the rotation frequency and the vibration frequency work together to affect the layering and separation effect of mineral particles. When the rotation frequency is high, the motion speed of the mineral particles on the separation disc increases, which may increase the risk of light minerals being mistakenly selected into the concentrate, thereby affecting the grade of the concentrate. Conversely, when the rotation frequency is low, the motion speed of the mineral particles on the separation disc slows down, which helps the settlement and layering of heavy minerals, but may reduce the processing capacity and recovery rate.

[0048] It should be noted that the aspects not described in detail in the present application are conventional operating means in the art and are not the focus of the present application, such as the specific method of wet magnetic separation.

[0049] The technical solutions of the present application are further illustrated by the following examples.

[0050] Example 1

[0051] A weathered ilmenite from Yunnan was used as the mineral sample, the TiO2 content in the raw ore was 5.25wt%, the TFe (total iron in the raw ore) content was 12.57wt%, and the particle size of 2-5mm in the mineral sample accounted for 85.3wt%. The ore was a placer ore mainly composed of ilmenite and titanomagnetite, and the associated gangue minerals were mainly montmorillonite, plagioclase, potassium feldspar and quartz.

[0052] The beneficiation method of the weathered ilmenite is as follows:

[0053] (1) The weathered ilmenite ore is ground to a content of -74 μm particle size of 45 wt%, and wet low-intensity magnetic separation is performed at a magnetic field strength of 0.18 T (since the magnetic field strength is low at this time, it is referred to as low-intensity magnetic separation), to obtain a low-intensity rough concentrate and a low-intensity tailing;

[0054] (2) The low-intensity rough concentrate is ground to a content of -38 μm particle size of 75 wt%, and wet low-intensity magnetic separation is performed at a magnetic field strength of 0.15 T, to obtain an iron concentrate and a titanium-bearing iron middling;

[0055] (3) The low-intensity tailing is subjected to high-intensity rough magnetic separation at a magnetic field strength of 1.0 T (since the magnetic field strength is high at this time, it is referred to as high-intensity magnetic separation), to obtain a high-intensity concentrate and a high-intensity tailing (directly discharged as tailing);

[0056] (4) The high-intensity concentrate is subjected to once spiral chute separation at a feed density of 40%, a longitudinal inclination of 0.6°, and a horizontal inclination of 9°, to obtain a spiral chute I rough concentrate, a spiral chute I middling, and a spiral chute I tailing (directly discharged as tailing);

[0057] (5) The spiral chute I rough concentrate is subjected to twice spiral chute separation at a feed density of 40%, a longitudinal inclination of 0.6°, and a horizontal inclination of 9°, to obtain a spiral chute II rough concentrate, a spiral chute II middling, and a spiral chute II tailing (directly discharged as tailing);

[0058] (6) The spiral chute II rough concentrate is subjected to twice spiral chute separation at a feed density of 40%, a longitudinal inclination of 0.6°, and a horizontal inclination of 9°, to obtain a spiral chute III rough concentrate, a spiral chute III middling, and a spiral chute III tailing (directly discharged as tailing);

[0059] (7) The spiral chute III rough concentrate is classified, +0.05 mm material is ground and returned, and -0.05 mm material is used as high-intensity separation material, and high-intensity magnetic separation is performed at a magnetic field strength of 0.6° T, to obtain a titanium concentrate and a titanium middling;

[0060] (8) The spiral chute middlings obtained in steps (4) to (6) are ground to a content of -74 μm particle size of 85 wt%, and combined with the titanium-bearing iron middling obtained by low-intensity magnetic separation and the titanium middling obtained by high-intensity magnetic separation, and rough separation is performed by a suspension cone separator at a rotation frequency of 15 Hz and a vibration frequency of 15 Hz, to obtain a rough concentrate and a tailing (directly discharged as tailing);

[0061] (9) The rough concentrate obtained by suspension cone separation is subjected to fine separation by a suspension cone separator at a rotation frequency of 10 Hz and a vibration frequency of 15 Hz, to obtain a titanium concentrate and a tailing (directly discharged as tailing).

[0062] Test results: The iron concentrate obtained in this example has an iron grade of 62.45% and an iron recovery of 30.35%; the titanium concentrate obtained by strong magnetic separation has a TiO2 grade of 47.66% and a titanium recovery of 42.45%; the titanium concentrate obtained by suspension cone separator has a TiO2 grade of 42.15% and a titanium recovery of 22.18%; the comprehensive titanium concentrate has a TiO2 grade of 45.61% and a titanium recovery of 64.63%.

[0063] Example 2

[0064] A weathered ilmenite in Yunnan was used as a sample, the TiO2 content in the raw ore was 8.35wt%, the TFe content was 15.43wt%, the particle size of 2-5mm accounted for 75.6wt% of the sample, the ore was a placer mainly composed of ilmenite and titanomagnetite, and the associated gangue minerals were mainly montmorillonite, plagioclase, potassium feldspar, augite and quartz.

[0065] The beneficiation method of the weathered ilmenite was as follows:

[0066] (1) The weathered ilmenite was ground to a particle size of 50wt% of-74μm, and wet low-intensity magnetic separation was carried out at a magnetic field intensity of 0.20T to obtain a low-intensity rough concentrate and a low-intensity tailings;

[0067] (2) The low-intensity rough concentrate was ground to a particle size of 80wt% of-38μm, and wet low-intensity magnetic separation was carried out at a magnetic field intensity of 0.12T to obtain an iron concentrate and a titanium-containing iron middlings;

[0068] (3) The low-intensity tailings were subjected to rough strong magnetic separation at a magnetic field intensity of 1.2T to obtain a strong magnetic concentrate and a strong magnetic tailings (directly discharged) ;

[0069] (4) The strong magnetic concentrate was subjected to one-time spiral chute separation at a feed density of 50wt%, a longitudinal inclination of 0.6° and a horizontal inclination of 9° to obtain a spiral chute I rough concentrate, a spiral chute I middlings and a spiral chute I tailings (directly discharged) ;

[0070] (5) The spiral chute I rough concentrate was subjected to two-time spiral chute separation at a feed density of 50wt%, a longitudinal inclination of 0.6° and a horizontal inclination of 9° to obtain a spiral chute II rough concentrate, a spiral chute II middlings and a spiral chute II tailings (directly discharged) ;

[0071] (6) The spiral chute II rough concentrate was subjected to two-time spiral chute separation at a feed density of 50wt%, a longitudinal inclination of 0.6° and a horizontal inclination of 9° to obtain a spiral chute III rough concentrate, a spiral chute III middlings and a spiral chute III tailings (directly discharged) ;

[0072] (7) The screw lo III rough concentrate is classified, the +0.05 mm material is ground and returned, and the -0.05 mm material is used as a strong magnetic separation material, and a titanium concentrate and a titanium middling are obtained under a magnetic field strength of 0.7 T;

[0073] (8) The screw lo middling obtained in steps (4)-(6) is ground to a -74 μm particle size content of 95 wt%, and is combined with the weak magnetic separation titanium-containing iron middling and the strong magnetic separation titanium middling, and is subjected to a suspension cone separator roughing under a rotation frequency of 18 Hz and a vibration frequency of 18 Hz, to obtain a rough concentrate and a tailing (directly discharged) ;

[0074] (9) The rough concentrate obtained by the suspension cone separation is subjected to a suspension cone separator cleaning under a rotation frequency of 14 Hz and a vibration frequency of 18 Hz, to obtain a titanium concentrate and a tailing (directly discharged).

[0075] Test results: The iron concentrate obtained in this example has a grade of 62.13% and an iron recovery rate of 35.15%; the titanium concentrate obtained by the strong magnetic separation has a TiO2 grade of 47.63% and a titanium recovery rate of 48.51%; the titanium concentrate obtained by the suspension cone separator cleaning has a TiO2 grade of 43.15% and a titanium recovery rate of 19.44%; and the comprehensive titanium concentrate has a TiO2 grade of 46.26% and a titanium recovery rate of 67.95%.

[0076] Example 3

[0077] A weathered titanimagite in Yunnan is used as a mineral sample, the TiO2 content in the raw ore is 10.15 wt%, the TFe content is 17.85 wt%, the 2-5 mm size fraction of the mineral sample accounts for 72.5 wt%, and the associated gangue minerals mainly include kaolin, plagioclase, potassium feldspar, augite and olivine.

[0078] The mineral processing method of the weathered titanimagite is as follows:

[0079] (1) The weathered titanimagite raw ore is ground to a -74 μm particle size content of 65 wt%, and is subjected to a wet type weak magnetic separation under a magnetic field strength of 0.18 T, to obtain a weak magnetic rough concentrate and a weak magnetic tailing;

[0080] (2) The weak magnetic rough concentrate is ground to a -38 μm particle size content of 85 wt%, and is subjected to a wet type weak magnetic separation under a magnetic field strength of 0.1 T, to obtain an iron concentrate and a titanium-containing iron middling;

[0081] (3) The weak magnetic tailing is subjected to a strong magnetic roughing under a magnetic field strength of 1.2 T, to obtain a strong magnetic concentrate and a strong magnetic tailing (directly discharged) ;

[0082] (4) the strong magnetic concentrate is subjected to one spiral chute separation at a feed density of 60%, a longitudinal inclination of 0.6° and a horizontal inclination of 9° to obtain spiral chute I rough concentrate, spiral chute I middlings and spiral chute I tailings (directly discharged tailings);

[0083] (5) the spiral chute I rough concentrate is subjected to two spiral chute separations at a feed density of 60%, a longitudinal inclination of 0.6° and a horizontal inclination of 9° to obtain spiral chute II rough concentrate, spiral chute II middlings and spiral chute II tailings (directly discharged tailings);

[0084] (6) the spiral chute II rough concentrate is subjected to two spiral chute separations at a feed density of 60%, a longitudinal inclination of 0.6° and a horizontal inclination of 9° to obtain spiral chute III rough concentrate, spiral chute III middlings and spiral chute III tailings (directly discharged tailings);

[0085] (7) the spiral chute III rough concentrate is subjected to classification, +0.05 mm material is ground and returned, and -0.05 mm material is used as strong magnetic separation material and subjected to strong magnetic separation at a magnetic field strength of 0.5 T to obtain titanium concentrate and titanium middlings;

[0086] (8) the spiral chute middlings obtained in steps (4)-(6) are ground to a -74 μm particle size content of 90 wt%, and combined with weak magnetic separation titanium-containing iron middlings and strong magnetic separation titanium middlings, and subjected to suspension cone separator rough separation at a rotation frequency of 20 Hz and a vibration frequency of 20 Hz to obtain rough concentrate and tailings (directly discharged tailings);

[0087] (9) the suspension cone separation rough concentrate is subjected to suspension cone separator cleaning at a rotation frequency of 15 Hz and a vibration frequency of 20 Hz to obtain titanium concentrate and tailings (directly discharged tailings).

[0088] Test results: the iron concentrate obtained in the example has an iron grade of 61.55% and an iron recovery rate of 34.65%; the titanium concentrate obtained by strong magnetic separation has a TiO2 grade of 46.16% and a titanium recovery rate of 50.56%; the titanium concentrate obtained by suspension cone separator cleaning has a TiO2 grade of 42.75% and a titanium recovery rate of 20.74%; the comprehensive titanium concentrate has a TiO2 grade of 45.42% and a titanium recovery rate of 71.3%.

[0089] Comparative Example 1

[0090] The beneficiation method of the present comparative example is the same as that of Example 1, except that a spiral chute is used instead of the roughing and cleaning of the suspension cone concentrator in steps (8) and (9). The specific method is as follows: steps (1)-(7) are the same as those of Example 1, step (8): the spiral chute is used to separate the spiral chute middlings obtained in steps (4)-(6) that have been ground to a particle size of -74 μm accounting for 90 wt%, and the weak magnetic cleaning titanium-containing iron middlings and the strong magnetic cleaning titanium middlings are combined, and the first spiral chute separation is carried out at a feed density of 40 wt%, a longitudinal inclination of 0.6° and a horizontal inclination of 9°, to obtain the first spiral chute concentrate, the first spiral chute middlings and the first spiral chute tailings, wherein the first spiral chute middlings and the first spiral chute tailings are directly discharged, and the first spiral chute concentrate is subjected to the second spiral chute separation at a feed density of 40 wt%, a longitudinal inclination of 0.6° and a horizontal inclination of 9°, to obtain the second spiral chute concentrate (i.e. titanium concentrate), the second spiral chute middlings and the second spiral chute tailings that are directly discharged.

[0091] The Ti02grade of the titanium concentrate obtained by the spiral chute cleaning is 38.75%, and the titanium recovery rate is 16.21%.

[0092] Comparative Example 2

[0093] The beneficiation method of the present comparative example is the same as that of Example 1, except that a spiral chute is used instead of the roughing and cleaning of the suspension cone concentrator in steps (8) and (9). The specific method is as follows: steps (1)-(7) are the same as those of Example 1, step (8): the spiral chute is used to separate the spiral chute middlings obtained in steps (4)-(6) that have been ground to a particle size of -74 μm accounting for 90 wt%, and the weak magnetic cleaning titanium-containing iron middlings and the strong magnetic cleaning titanium middlings are combined, and the first spiral chute separation is carried out at a feed density of 40 wt%, a longitudinal inclination of 0.6° and a horizontal inclination of 9°, to obtain the first spiral chute concentrate, the first spiral chute middlings and the first spiral chute tailings, wherein the first spiral chute middlings and the first spiral chute tailings are directly discharged, and the first spiral chute concentrate is subjected to the second spiral chute separation at a feed density of 40 wt%, a longitudinal inclination of 0.6° and a horizontal inclination of 9°, to obtain the second spiral chute concentrate (i.e. titanium concentrate), the second spiral chute middlings and the second spiral chute tailings that are directly discharged.

[0094] The Ti02grade of the titanium concentrate obtained by the spiral chute cleaning is 39.05%, and the titanium recovery rate is 12.31%.

[0095] Comparative Example 3

[0096] The beneficiation method of the present comparative example is the same as that of Example 2, except that a spiral chute is used instead of the roughing and cleaning of the suspension cone concentrator, and the specific method is the same as that of Comparative Example 1.

[0097] The titanium concentrate obtained by spiral chute concentration has a TiO2 grade of 39.12% and a titanium recovery rate of 14.12%.

[0098] Comparative Example 4

[0099] The beneficiation method of the present comparative example is the same as that of Example 2, except that a shaking table is used instead of a suspension cone concentrator for roughing and cleaning, and the specific method is the same as that of Comparative Example 2.

[0100] The titanium concentrate obtained by shaking table cleaning has a TiO2 grade of 39.23% and a titanium recovery rate of 11.05%.

[0101] Comparative Example 5

[0102] The beneficiation method of the present comparative example is the same as that of Example 3, except that a spiral chute is used instead of a suspension cone concentrator for roughing and cleaning, and the specific method is the same as that of Comparative Example 1.

[0103] The titanium concentrate obtained by spiral chute cleaning has a TiO2 grade of 38.68% and a titanium recovery rate of 14.48%.

[0104] Comparative Example 6

[0105] The beneficiation method of the present comparative example is the same as that of Example 3, except that a shaking table is used instead of a suspension cone concentrator for roughing and cleaning, and the specific method is the same as that of Comparative Example 2.

[0106] The titanium concentrate obtained by shaking table cleaning has a TiO2 grade of 39.13% and a titanium recovery rate of 10.84%.

[0107] From the above comparative test results, it can be seen that the suspension cone concentrator in the present application can realize fine separation of titanium-containing middlings, and compared with conventional spiral chutes and shaking tables, it can increase the titanium iron ore concentrate recovery rate by 5-10 percentage points and the concentrate grade by more than 3 percentage points.

[0108] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any changes or replacements easily thought of by those skilled in the art within the technical range disclosed by the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for beneficiating weathered ilmenite, characterized in that: The iron concentrate and the titanium-containing iron middlings are obtained by stage grinding and stage weak magnetic separation; the weak magnetic tailings are subjected to strong magnetic roughing separation to obtain strong magnetic concentrate and strong magnetic tailings; the strong magnetic concentrate is separated by three spiral chutes to obtain spiral products, which include spiral coarse concentrate, spiral middlings and spiral tailings; the spiral coarse concentrate is subjected to graded closed-circuit grinding and strong magnetic separation to obtain titanium concentrate and strong magnetic titanium middlings; the spiral middlings are ground, combined with the titanium-containing iron middlings and the strong magnetic titanium middlings for secondary separation by a suspended vibration cone concentrator to obtain titanium concentrate; The stage weak magnetic separation includes: grinding the weathered ilmenite ore and then performing wet weak magnetic separation to obtain weak magnetic coarse concentrate and weak magnetic tailings; grinding the weak magnetic coarse concentrate and performing wet weak magnetic separation to obtain iron concentrate and ilmenite-containing middlings.

2. The beneficiation method of weathered ilmenite according to claim 1, characterized in that: The following steps are involved: (1) The weathered ilmenite ore is ground and then subjected to wet weak magnetic separation to obtain weak magnetic coarse concentrate and weak magnetic tailings; (2) grinding and wet weak magnetic separation of the weak magnetic coarse concentrate to obtain iron concentrate and titanium-containing iron middlings; (3) subjecting the weak magnetic tailings to strong magnetic roughing to obtain strong magnetic concentrate and strong magnetic tailings; (4) performing a first spiral chute separation on the strong magnetic concentrate to obtain spiral chute I coarse concentrate, spiral chute I middlings and spiral chute I tailings; (5) subjecting the spiral chute I coarse concentrate obtained in step (4) to a second spiral chute separation to obtain spiral chute II coarse concentrate, spiral chute II middlings, and spiral chute II tailings; (6) The spiral chute II coarse concentrate obtained in step (5) is subjected to a third spiral chute separation to obtain spiral chute III coarse concentrate, spiral chute III middlings and spiral chute III tailings; (7) subjecting the spiral III coarse concentrate obtained in step (6) to graded closed-circuit grinding and strong magnetic separation to obtain titanium concentrate and titanium middlings; (8) Grinding the spiral ore I, spiral ore II and spiral ore III, and subjecting them to rough separation with the titanium-containing iron ore obtained in step (2) and the titanium ore obtained in step (7) using a suspended cone concentrator to obtain a coarse concentrate and tailings; (9) The coarse concentrate obtained in step (8) is subjected to concentrating by a suspended vibration cone concentrator to obtain titanium concentrate and tailings.

3. The beneficiation method of weathered ilmenite according to claim 2, characterized in that: In step (1), the particle size of the weathered ilmenite ore is 2-5 mm, and the grinding is performed to grind the ore to a fineness of -74 μm with a particle size content of 45-65 wt%; and / or The magnetic field strength of the wet weak magnetic separation is 0.15~0.2T.

4. The beneficiation method of weathered ilmenite according to claim 2, characterized in that: In step (2), the grinding is grinding to a fineness of -38 μm with a particle size content of 75 to 85 wt%; and / or The magnetic field strength of the wet weak magnetic separation is 0.1~0.15T.

5. The beneficiation method of weathered ilmenite according to claim 2, characterized in that: In step (3), the magnetic field strength of the strong magnetic roughing is 0.8~1.2T.

6. The beneficiation method of weathered ilmenite according to claim 2, characterized in that: In steps (4) to (6), when the spiral chute is separated, the feed concentration is 40-60 wt%, the longitudinal inclination angle is 0.6°, and the horizontal inclination angle is 9°.

7. The beneficiation method of weathered ilmenite according to claim 2, characterized in that: In step (7), the grading closed-circuit grinding is carried out with a grading limit of 0.05 mm, the +0.05 mm material is ground, and the -0.05 mm material is regarded as a qualified product; and / or The magnetic field strength of the strong magnetic selection is 0.6~0.8T.

8. The beneficiation method of weathered ilmenite according to claim 2, characterized in that: In step (8), the grinding is grinding to a fineness of -74 μm with a particle size content of 85 to 95 wt%; and / or The rotation frequency of the suspended vibration cone concentrator is 15~20 Hz, and the vibration frequency is 15~20 Hz.

9. The beneficiation method of weathered ilmenite according to claim 2, characterized in that: In step (9), the rotation frequency of the suspended cone concentrator is 10-15 Hz, and the vibration frequency is 15-20 Hz.

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